<template>
  <div class="star" :class="'star-' + size">
    <span class="star-item" v-for="(star, index) in starArr" :key="index" :class="star"></span>
  </div>
</template>
 
<script>
export default {
  data() {
    return {};
  },
  props: {
    rating: Number, // 评分
    size: Number, // 图片大小
  },
  computed: {
    starArr() {
      const arr = [];
      const { rating }  = this;
      // 添加类名 'on'
      const onCount = Math.floor(rating);
      for (let i = 0; i < onCount; i++) {
        arr.push('on')
      }
      // 添加类名 'half', 注意小数相减精度的问题
      const count = rating * 10 - onCount * 10;
      if (count >= 5) {
        arr.push('half')
      }
      // 添加类名 'off'
      while(arr.length < 5) {
        arr.push('off')
      }

      return arr;
    }
  }
};
</script>
 
<style scoped lang = "stylus">
  @import "../../common/stylus/minxins.styl"
  .star //2x图 3x图
    float left
    font-size 0
    .star-item
      display inline-block
      background-repeat no-repeat
    &.star-48
      .star-item
        width 20px
        height 20px
        margin-right 22px
        background-size 20px 20px
        &:last-child
          margin-right: 0
        &.on
          bg-image('./images/star48_on')
        &.half
          bg-image('./images/star48_half')
        &.off
          bg-image('./images/star48_off')
    &.star-36
      .star-item
        width 15px
        height 15px
        margin-right 6px
        background-size 15px 15px
        &:last-child
          margin-right 0
        &.on
          bg-image('./images/star36_on')
        &.half
          bg-image('./images/star36_half')
        &.off
          bg-image('./images/star36_off')
    &.star-24
      .star-item
        width 10px
        height 10px
        margin-right 3px
        background-size 10px 10px
        &:last-child
          margin-right 0
        &.on
          bg-image('./images/star24_on')
        &.half
          bg-image('./images/star24_half')
        &.off
          bg-image('./images/star24_off')
</style>